Herrmann's catalyst

Herrmann's catalyst is an organopalladium compound that is a popular catalyst for the Heck reaction. It is a yellow air-stable solid that is soluble in organic solvents. Under conditions for catalysis, the acetate group is lost and the Pd-C bond undergoes protonolysis, giving rise to a source of "PdP(o\-tol)3".

The complex is made by reaction of tris(o-tolyl)phosphine with palladium(II) acetate:


 * 2 Pd(OAc)2 + 2 P(o\stolyl)3 -> 2 HOAc + Pd2(OAc)2[P(o\stolyl)(o\stolyl)2]2

Many analogues of Hermann's catalyst have been developed, e.g. palladacycles obtained from 2-aminobiphenyl.